<!DOCTYPE>
<html>
<head>
<meta charset="utf-8" />
<title>简易计算器</title>
<style type="text/css"  />

* { padding: 0; margin: 0; }
li { list-style: none; }
body { background: #940032; }

#counter { width: 500px; height: 420px; background:#939; margin: 50px auto 0; position: relative; }
#counter h2 { line-height: 42px; padding-left: 15px; font-size: 14px; font-family: arial; color: #eee; }
#counter a { font-weight: normal; text-decoration: none; color: #ff3333; }
#counter a:hover { text-decoration: underline; }
#bg { width: 280px; height: 200px; border: 3px solid #680023; background: #990033; filter: alpha(opacity=80); opacity: 0.8; position: absolute; left: 50%; top: 115px; margin-left: -141px; }
#counter_content { width: 250px; position: absolute; top: 130px; left: 130px; z-index: 1; }
#counter_content h3 { margin-bottom: 10px; }
#counter_content h3 input { border: none; width: 243px; height: 30px; line-height: 30px; padding: 0 10px; background: url(images/ico.png) no-repeat; text-align: right; color: #333; font-size: 14px; font-weight: bold; }
#counter_content div { width: 250px; }
#counter_content input { width: 60px; height: 30px; line-height: 30px; float: left; background: url(images/ico.png) no-repeat -303px 0; text-align: center; color: #fff; cursor: pointer; margin: 0 1px 4px 0; border:0; }
#counter_content div > input:hover { background: url(images/ico.png) no-repeat -243px 0; }
#counter p { width: 500px; position: absolute; bottom: 20px; left: 0; color: #ff3333; text-align: center; font-size: 12px; }
</style>
</head>
</head>

<body>

<div id="counter">
	<h2>简易计算</h2>
	<div id="counter_content">
		<h3><input id="input1" type="text" value="0" /></h3>
		<div id="div1">
			<input type="button" value="7" onclick="kick('7')"/>
            <input type="button" value="8" onclick="kick('8')"/>
            <input type="button" value="9" onclick="kick('9')"/>
            <input type="button" value="+" onclick="kick('+')"/>
            <input type="button" value="4" onclick="kick('4')"/>
            <input type="button" value="5" onclick="kick('5')"/>
            <input type="button" value="6" onclick="kick('6')"/>
            <input type="button" value="-" onclick="kick('-')"/>
            <input type="button" value="1" onclick="kick('1')"/>
            <input type="button" value="2" onclick="kick('2')"/>
            <input type="button" value="3" onclick="kick('3')"/>
            <input type="button" value="*" onclick="kick('*')"/>
            <input type="button" value="0" onclick="kick('0')"/>
            <input type="button" value="C" onclick="kick('C')"/>
            <input type="button" value="=" onclick="kick('=')"/>
            <input type="button" value="/" onclick="kick('/')"/>
		</div>
	</div>
	
	
</div>
</body>
<script type="text/javascript">
	var oInput = document.getElementById("input1");
	
	var opt = ""; //预存操作符
	var sNum1 = ""; //预存第一个数字
	var isAppend = true; //是否要追加数字
	
	function kick(btn){
		switch(btn) {
			case "=":
				oInput.value = cal(sNum1 , oInput.value, opt);
				break;
			case "+":
			case "-":
			case "*":
			case "/":
				oInput.value = cal(sNum1 , oInput.value, opt);
				opt = btn;
				isAppend = false;
				sNum1 = oInput.value
				break;
			case "C":
				opt = "";
				sNum1 = "";
				oInput.value = "0";
				break;
			default:
				oInput.value = oInput.value == "0" ? "" : oInput.value;
				if(opt == "" || isAppend) {
					oInput.value += btn;
				} else {
					oInput.value = btn;
					isAppend = true;
				}
				
		}
	}
	
	function cal(num1 , num2 , opt){
		switch(opt) {
			case "+" : return Number(num1)+Number(num2);
			case "-" : return Number(num1)-Number(num2);
			case "*" : return Number(num1)*Number(num2);
			case "/" : return Number(num1)/Number(num2);
			default: return Number(oInput.value);
		}
	}
</script>
</html>



















